I'm no gearhead, but something tells me meth isn't good for your engine.

It's certainly not good if you're stopped by police on I-35. Round Rock police stopped a car Saturday and asked the occupants some questions. When no one could get their stories straight, a K-9 unit was called and 71 pounds of methamphetamine were found inside a modified gas tank.

Police say the street value of the meth was close to $2 million.

KXAN reports that 36-year-old Nathan Leon Fields of Theodore, Alabama was arrested and charged with manufacture or delivery of a controlled substance.

We checked the Williamson County Jail inmate roster, and Fields was still in the jail as of 2 PM Thursday, May 10 in lieu of $70,000 bond.

Nathan Leon Fields - Williamson County Jail Photos